The reaction of the present invention is included in a category of reaction classified as the Ullmann condensation reaction.
The Ullmann condensation reaction has been discovered by F. Ullmann (Chem. Ber., 36, 2382 (1903)) in which an aromatic amine and an aromatic halogen compound, preferably an aromatic iodide compound, are subjected to a coupling reaction in the presence of a base and a copper catalyst.
In the prior art, an alkylbenzene, a halogenobenzene, nitrobenzene or the like aromatic compound, or decane, tridecane or the like saturated aliphatic hydrocarbon compound, having an ionization potential of 9.1 eV or more is used as the solvent in this reaction.
In addition, cyclic nitrogen-containing compounds such as pyridines, quinolines and the like are used as the reaction solvent as a means for accelerating the reaction (for example, Tetrahedron Lett., 4531 (1965), Tetrahedron Lett., 679 (1966)).
However, the aforementioned reaction in which an aromatic compound or a saturated aliphatic hydrocarbon compound is used as the solvent generally takes a prolonged period of reaction time and requires a considerably high temperature for achieving practical arylation rate, thus posing a problem in that by-products are formed due to oxidation of substituent groups and dimerization of the formed product.
Also, in the case of the use of cyclic nitrogen-containing compounds such as pyridines, quinolines and the like as the reaction solvent as a means for accelerating the reaction, the problem of causing by-product formation is still unsolved.
In addition, since separation and purification of such by-products are extremely difficult, high degree purification of the arylamine with the aim of using it as a raw material for electronic material use or as an intermediate thereof causes problems in that its production yield is reduced or the product is not practical due to high cost.
As described in the foregoing, a practical method for producing an arylamine with a high purity and in a high yield or at a low cost has not been developed yet.